Dynamic search engine results employing user behavior

ABSTRACT

A method and apparatus for dynamically modifying search results “on the fly” based on the behavior of the user currently conducting a search. In one embodiment, data regarding user behavior is gathered from virtually any activity, including clicks on links, dwell times, downloads, transactions and cursor movements. Subordinate keywords are generated to reflect the intent of the user as inferred from the user&#39;s behavior. Subordinate keywords, as opposed to traditional primary keywords, are keywords that are identified as important to the search, but are not necessarily essential for a matched document. They are automatically generated by the system from a variety of places, such as documents clicked on by the user as well as documents that are skipped. The system uses the subordinate keywords to dynamically re-rank matched documents and advertisements to best reflect the inferred intent of the user in order to continuously provide the most relevant results.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/510,524, filed Aug. 25, 2006, entitled “Dynamic Search Engine ResultsEmploying User Behavior,” which application claims the benefit of U.S.Provisional Patent Application No. 60/796,624, filed May 2, 2006,entitled “Dynamic Search Engine Results Using User Behavior,” whichapplications are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to search engines which generate resultswith improved relevance by monitoring user actions.

Search engines are designed to explore data communications networks fordocuments of interest to a given user and then generate listings ofresults based on those documents identified in that search. The userspecifies this interest by inputting a query, expressed as a “keyword”or set of “keywords,” into the search engine. The keywords are thencompared with terms from documents previously indexed by the searchengine in order to produce a set of matched documents. Finally, beforebeing presented, the matched documents are ranked by employing anynumber of different algorithms designed to determine the order withwhich documents might be relevant to the user. The objective is toquickly point the user toward those matched documents with the greatestlikelihood of producing satisfaction.

On the internet (a popular, global data communications network) thenumber of indexed documents has been growing rapidly due predominantlyto improvements in technology and the growth in the quantity ofinformation available. Some queries now return millions of matcheddocuments. As a result, the ability of internet search engines to helpusers identify documents of particular interest to a given query isbeing hampered. In other words, while internet users have access to anincreasing quantity of potentially relevant information, using keywordqueries on search engines to identify those documents that producesatisfaction has become more difficult.

Search engines have thus begun employing many strategies in an attemptto combat this problem. Primarily these consist of improving thealgorithms that rank the relevancy of matched documents so that, as thequantity of results increases, those most relevant will still be easilyaccessible at the top of the list. Some of the major strategies consistof focusing on specific vertical segments, using artificial intelligenceto perform contextualized searches, employing personalization,leveraging psychographic, demographic and geographic information andmining the search behaviors of previous users. (Using the behavior ofprevious users to predict the relevancies of documents for future usershas been covered by a number of U.S. patents and applications:2006/0064411 A1 entitled “Search engine using user intent,” U.S. Pat.No. 6,738,764 B2 entitled “Apparatus and method for adaptively rankingsearch results,” and U.S. Pat. No. 6,370,526 B1 entitled “Self-adaptivemethod and system for providing a user-preferred ranking order of objectsets,” to name a few.)

While all of these strategies, used either singularly or in combination,provide some benefit, they are incomplete for the simple reason thatthey do not take into account the behavior of the specific userconducting the search at the moment the search is actually beingconducted. Consequently, there is a lot of room to adjust and improvethe relevancies of matched documents by examining the behavior of thecurrent user and then responding accordingly in real time.

To illustrate, consider a user who submits a query using the keyword“Washington.” Different algorithms, using the strategies mentioned aboveor potentially others, can be deployed to determine which documentsmight have the highest probability of being relevant to that specificuser for that particular query. By using only information availableprior to the submission, however, there is no way of knowing a priori,with any significant degree of certainty, if the user is more interestedin “Washington University,” “George Washington,” or, for that matter,“George Washington University.” Thus, while the search engine, employingwhatever algorithms and strategies it deems best, attempts to presentthe results in the most relevant order possible, without additionalinformation from the user there is a substantial chance that the resultswill be littered with irrelevant documents.

At this point the users' options are limited. They can scan page by pagethrough potentially millions of extraneous matched documents in anattempt to pick out the ones that matter or they can try to identifyadditional or more specific keywords in an attempt to produce new, andhopefully more relevant, sets of results. Depending on the nature of thesearch and the ingenuity of the user, this task can often be painstakingand frustrating, if not impossible.

There is therefore a need for a search engine capable of discerning theintent of the specific user currently conducting a search, at the momentthat search is being conducted, in order to dynamically modify thesearch results “on the fly” with the purpose of ranking the matcheddocuments in the most relevant order possible for that user.

SUMMARY OF THE INVENTION

The present invention provides a system for using the behavior of aspecific user to dynamically modify search results “on the fly” whilethe actual search is being conducted. The search engine of the preferredembodiment compiles information with respect to the behavior of the usercurrently conducting a search in order to infer the intent and interestsof that user thereby enabling the search engine to present morepertinent results by dynamically altering, in real time, therelevancies, and thus order, of the matched documents.

In one embodiment, a software application runs as a user interfacebetween a user and a standard third-party search engine, or multiplethird-party search engines with the user selecting the preferred. Sincethe initial results are pulled from the underlying engine they naturallytake advantage of all of the technologies and strategies, such as theexamples given above, which went into determining the relevancies andordering of the matching documents in that initial list.

From there, the system infers the intent of the current user bycollecting data regarding that user's behavior. In one embodiment, thesystem infers the user's intent from information gathered by virtue ofthe user clicking on documents during a search. In another embodiment,other aspects of user behavior, such as subsequent clicks on linkswithin documents, time spent looking at different documents (“dwelltime”), time spent looking at domains associated with differentdocuments, downloads, transactions, cursor movements, scrolling andhighlighting of text, images or other information, are also monitoredand used to infer the intent and interests of the user.

In one embodiment, the inferred intent of the user is characterized byusing subordinate keywords. Subordinate keywords, as opposed totraditional primary keywords, are keywords that are identified asimportant to the search, but are not necessarily essential for a matcheddocument. They are automatically generated by the system from a varietyof places, such as documents clicked on by the user during the searchprocess as well as documents that are ignored or skipped by the user.

In one embodiment, the system will then use the subordinate keywords todynamically re-rank the matched documents “on the fly” to continuouslyprovide the user with the most relevant results possible. The systemwill additionally use the subordinate keywords to dynamically alter anysponsored links in order to best reflect the intent and interests of theuser and, as such, provide the most relevant advertisements and as aresult enhance the revenue-generating capability of the system.

The outcome is a dynamic results search engine that is not only capableof taking advantage of all of the intelligence and technology of theunderlying search engine that went into generating the initial results,but better equipped to help users find the documents they desire byassisting them in navigating increasingly ponderous lists of matcheddocuments in search results.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of one embodiment of a system incorporating thepresent invention.

FIG. 2A is a diagram of one embodiment of the home page.

FIG. 2B is a diagram of one embodiment of the initial search results.

FIG. 2C is a diagram of one embodiment of the re-ranked search results.

FIG. 2D is a diagram of one embodiment of the search results re-rankedagain.

FIG. 3 is a flowchart of one embodiment of the invention.

FIG. 4 is a flowchart of one embodiment of subordinate keywordgeneration and re-ranking of results.

FIG. 5 is a diagram of one embodiment of the advanced search resultsdisplaying subordinate keywords.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of the present invention operates on theinternet, and more specifically the World Wide Web. The presentinvention, however, is not limited to the internet, the World Wide Webor any other particular network architecture, software or hardware whichmay be described herein. The invention is appropriate for any othernetwork architectures, hardware and software. Furthermore, while thefollowing description relates to an embodiment utilizing the internetand related protocols, other networks and protocols, for example, foruse with interactive TVs, cell phones, personal digital assistants andthe like, can be used as well.

The functions described herein are performed by programs includingexecutable code or instructions running on one or more general-purposecomputers. The functions described herein, however, can also beimplemented using special purpose computers, state machines and/orhardwired electronic circuits. The example processes described herein donot necessarily have to be performed in the described sequence and notall states have to be reached or performed.

As used herein, the term “website” refers to a collection of content.Website content is often transmitted to users via one or more serversthat implement basic internet standards. “Website” is not intended toimply a single geographic or physical location but also includesmultiple geographically distributed servers that are interconnected viaone or more communications systems.

As used herein, the term “document” is defined broadly and includes anytype of content, data or information contained in computer files andwebsites. Content stored by servers and/or transmitted via thecommunications networks and systems described herein may be stored as asingle document, a collection of documents or even a portion of adocument. The term “document” is not limited to computer filescontaining text but also includes files containing graphics, audio,video and other multimedia data. Documents and/or portions of documentsmay be stored on one or more servers.

As used herein, the term “click” or “click-through” is defined broadlyand refers to clicking on a hyperlink included within search resultlistings to view an underlying document or website. The term “clickingon” a link or button, or pressing a key to provide a command or make aselection, may also refer to using other input techniques such as voiceinput, pen input, mousing or hovering over an input area or the like.

The dynamic results search engine of the preferred embodiment compilesinformation with respect to the behavior of the user currentlyconducting a search in order to infer the interests and intent of thatuser thereby enabling the search engine to present more pertinentresults by dynamically altering the relevancies, and thus order, of thematched documents “on the fly.” The categories of user behavior acquiredmay include search terms that resulted in click-throughs to particularwebpages, websites and sub-domains visited, dwell time, and actionstaken at the webpages including document downloads and financialtransactions.

FIG. 1 is a high-level illustration of a preferred embodiment of asystem incorporating the present invention. Documents on servers orcomputers 110-118 on a data communication network 140, such as theinternet, are scanned and indexed by search engines on computers andassociated databases 120-128. On the internet there are currentlybillions of documents available, with more being added daily. Google,Yahoo!, MSN and Ask are examples of popular internet search engines, butmost any web site that enables users to search documents on a datacommunications network and retrieve relevant results can be considered asearch engine. Users on computers or terminals 100-108 seekinginformation can connect with the search engine of their choice, enterkeywords related to their searches, and then retrieve lists of matcheddocuments, normally sorted and ranked by some sort of algorithm thatplaces the ones deemed most relevant at the top. An embodiment of thepresent invention provides a server 132 and database 130 which plug intothe data communications network and then uses the behavior of currentusers to dynamically alter the results provided by one, if not several,of the other search engines.

The description of this system will focus on a website that takesresults from other search engines that reside on the internet, however,another embodiment of the system would involve incorporating the presentinvention directly into one of the other search engines 120-128. Ratherthan collecting the search results via a data communications network,the system can gather the results directly from the search engine andthen operate accordingly. As discussed briefly below, this embodimentwould actually offer some advantages in terms of modifying the rankingsof the matched documents. Another embodiment of the system would involvesoftware, which could be made available for download, that resides onthe users' computers or terminals 100-108. Now, rather than going to thewebsite of the invention, users can go directly to their search engineof choice and the process of dynamically altering search results will beperformed by the software located on the users' computers. Yet anotherembodiment of the invention involves utilizing its own search engine, asopposed to that of a third-party, should one be available.

FIG. 2A is a diagram of a home page of a preferred embodiment of theinvention. While other information and links can be present, theprincipal purpose of the home page is to enable the user to enter akeyword or set of keywords 202 representing the user's query beforeclicking on a button 204 to request that the search engine retrieve theresults.

FIG. 2B is a diagram of an example of a search results page depictingwhat the initial search results for the keyword “Washington” might looklike. Upon receiving a query 212 from a user, expressed as a keyword orset of keywords, the invention pulls the results 220-227 from anothersearch engine, using publicly available APIs, or some other method, suchas, for example, screen scraping, before presenting them to the user.The set of matched documents, and the order in which they are presented,is identical to that of the underlying search engine. It is in this waythat the present invention is able to benefit from all of thetechnologies and strategies used by the underlying search engine whenproducing the initial search results.

Sponsored links 230-238 are also made available for the purposes ofgenerating revenue for the system and enabling advertisers to offertheir products and services. A third-party ad delivery system, such asAdSense from Google, would be one way to accomplish delivering targetedsponsored links. Third-party ad delivery systems either accept keywordsubmissions or scan the content of a given web page, the search resultspage in this case, before returning the most relevant ads in theirnetworks. In this way the ads delivered will, to the extent possible,reflect the intent of the current user. Another embodiment would workdirectly with advertisers by enabling them to purchase keywords beforeintegrating their sponsored links where appropriate. A hybrid approach,involving the implementation of a third-party ad delivery system alongwith working directly with some advertisers, would be yet anotherembodiment.

Since the number of matched documents rarely fits on a single page,buttons, such as a next results button 216, are available to enableusers to navigate to subsequent pages of results or back to previouspages of results. It should also be noted that there is nothingpreventing an embodiment of the system from offering supplementalinformation on the search results page, as is often the case with searchengines, such as related popular queries, suggested spellings or linksto maps and stock quotes.

FIG. 2C is a diagram of an example of how the first modified resultsmight look after the user clicks on the document “George WashingtonUniversity” 226 from the initial results as depicted in FIG. 2B and thenreturns to the search results page. The initial set of matched documentsremains the same yet their order has changed based on the intelligencegathered as a consequence of the user's click on the document “GeorgeWashington University” 226. The system has determined that the user ismost likely interested in Universities named “Washington” as opposed toGeorge Washington the man or Washington the city or state. As a result,the “Access Washington Home Page” document 220, which was initially atthe top of the list, has fallen to the sixth position 255 because thesystem has deemed, based on the user's behavior, that the relevancy ofthis document has declined. On the other hand, the “University ofWashington” document 221, which was initially in the second position,has now moved to the top 250 because the system has deemed, again basedon the behavior of the user, that the relevance of this document hasincreased. This process continues, for all practical purposes, for eachdocument returned in the initial search results. (A discussion regardingpractical computation limits is below.)

As the relevancies and thus positions of the matched documents change,the sponsored links 260-268 and their positions also change to moreaccurately match the intent of the user as deduced by the system basedon the user's behavior. While the sponsored link “Visitor GuideWashington” 238 was present in the fifth position on the page with theinitial search results in FIG. 2B, it has been removed. Furthermore, thesponsored link “Online University Courses” 264, while not even presentin the initial results, is now in the third position. In the preferredembodiment, the sponsored links provided and the order in which they aredisplayed will be adjusted continuously, once again, based on the user'sbehavior. Not only will this provide a benefit to the user as morerelevant sponsored links are displayed, but the revenue-generatingability of the system will be enhanced as users will be more inclined toclick on the more relevant advertising.

FIG. 2D is a diagram of an example of how the second modified resultsmight look after the user clicks on the document “George WashingtonUniversity—Official Athletic Site” 256 in FIG. 2C and then returns againto the search results page. The order of the search results have onceagain changed based on this new intelligence gathered with respect tothe behavior of the user. The system has determined that the user ismost likely interested in athletics at George Washington University.Thus, the “University of Washington” document 287 has now moved to theeighth position after initially being in position two 221 in FIG. 2B andthen being moved, subsequent to the user's first action, to position one250 in FIG. 2C. While the system initially increased the relevance ofthis document after the first action, it was then decreased after theuser's second action. The document “George Washington University” 280has now moved to the top spot after initially being placed in theseventh position 226 in FIG. 2B and then promoted, subsequent to theuser's first action, to the second position 251 in FIG. 2C. This processcontinues, for all practical purposes, for each document returned in thefirst modified search results in FIG. 2C.

The sponsored links 290-298 have, once again, changed based on thebehavior of the user. “Try eBay” 294 and “‘Tuff Tear’ Paper Numbers” 296did not appear with the initial search results FIG. 2B or the searchresults presented after the user's first action FIG. 2C. The sponsoredlink “The Lodge at Suncadia” 298, while previously in the secondposition has been moved down to the fifth position.

FIG. 3 is a flowchart of one embodiment of the invention. The user'sexperience begins on the inventions home page 300 as depicted in FIG.2A. After entering a query, expressed as a keyword or set of keywords,the system produces an initial set of search results 302 as depicted inFIG. 2B. These results can be supplied by any third-party search engineor internally should the system comprise its own search engine.

Once the initial search results are presented, the system beginscollecting information regarding the user's behavior in an effort todivine the user's intent and interests and then adjust the resultsaccordingly. Data regarding user behavior immediately following theinitial search comes from anything related to the activity of the user,including, but not limited to, clicks on various links in the searchresults as well as subsequent clicks on links within documents, skippedlinks in the search results, dwell times, time spent looking atdocuments from specific domains, resources accessed, transactionsconducted, purchases made, orders placed, sessions created, documentsdownloaded, cursors moved, pages scrolled or text, images or otherinformation highlighted, or any combination thereof. In general, themore time spent looking and conducting activities at a particularwebsite, the more relevant that website is to the user.

The process continues by the user taking some form of action 304 such asselecting a document or going to the next page of results. In the caseof selecting a document, the user is taken to that document so that itcan be reviewed. While the document is being reviewed, the system willsimultaneously take information collected regarding the user's behaviorto re-rank the initial search results 308. If the user finds the desireddocument 310 on the first try, then the user is satisfied and theprocess is completed. However, should the user return to the searchresults page to continue the search process, the new search results,having been re-ranked while the user was away, will be displayed 312 asdepicted in FIG. 2C. The process then proceeds with the user performingdifferent actions while the system continues to collect data regardingthe user's behavior in order to deduce the user's intent and thenappropriately re-rank the search results. Each time the user returns tothe search results page, the matched documents will have been re-rankedbased on new intelligence gleaned from the user's behavior.

The primary mechanism for expressing the deduced intent of the user isthrough the use of “subordinate” keywords. Users typically executequeries with search engines by submitting a set of “primary” keywords.These primary keywords are matched by the search engines with their setsof indexed documents to produce lists of results which are thenprioritized using any number of different relevancy algorithms. Thematched documents produced, however, must, in one way or another,contain all of the primary keywords submitted for the query. In otherwords, the primary keywords are “all or nothing;” those documents thatdo not include the complete set of primary keywords are excluded.Subordinate keywords, on the other hand, are keywords that areidentified as important but are not necessarily essential to the query.They enable the system to give preferential treatment to (i.e. increasethe relevancy of) documents that contain a subset of those keywordswithout necessarily eliminating those that do not.

While many search engines offer “advanced” search functionality thatenables users to specify, for example, keywords that are not to appearor a set of keywords where at least one must be present, thesetechniques are complex and, even with a bit of manipulation, cannot beused to emulate the functionality or utility of subordinate keywords.Users who are sophisticated enough to avail themselves of the advancedsearch functionality commonly offered by search engines will stillreceive significant advantages from the present invention.

FIG. 4 is a flowchart of one embodiment of the process of generatingsubordinate keywords and re-ranking search results. As mentionedpreviously, when the user takes some sort of action 400 such asselecting a document or continuing to another page of results, thesystem generates subordinate keywords which are then added to the listof any that might already exist (step 402). Based on where thesubordinate keywords appear and with what frequency, the system thenassigns weights to, or adjusts the weights of, each subordinate keyword(step 404). These subordinate keywords, with their associated weights,are then used to adjust the relevancies of the documents in the searchresults (step 406). The new relevancies will be a function of the oldrelevancies in addition to a function of the weights, frequencies andlocations of appearances of the subordinate keywords in each of thematched documents. The new relevancies are then used to dynamicallyre-rank the documents in the search results (step 408) with the effectof moving the most relevant documents up while pushing the leastrelevant down.

Subordinate keywords are automatically generated by the system from avariety of places, including, but not limited to, links clicked on bythe user, other links associated with the document such as linkspointing to the document, “descriptive text” associated with eachdocument in the search results, meta-tags connected to viewed documents,and prominent words and phrases in viewed documents. (As is commonpractice with search engines, “stop words,” defined as those words whichare so common that they are useless to index, are ignored.) A thesauruscan also be used to generate similar words and phrases that might be ofinterest to the user. Since subordinate keywords are simply anexpression of important ideas, and do not as such eliminate any matcheddocuments from the results of a query, they can be employed withabundance. In fact, the more subordinate keywords are generated from theuser's behavior, the more likely the system is to find the most relevantdocuments and move them to the top of the search results.

For example, one embodiment of the system might generate subordinatekeywords from every word in the title and display text of any documentselected by virtue of a user's click. In FIG. 2B the title and displaytext for document 226 are, respectively, “George Washington University”and “The George Washington University is located four blocks from theWhite House and was created by an Act of Congress in 1821.” Therefore,if N represents the number of subordinate keywords generated, sk_(n)represents the n^(th) subordinate keyword and s_(n) represents thenumber of times that the n^(th) subordinate keyword appears in the titleand display text of the selected document, then TABLE I is ademonstration of the subordinate keywords generated from clicking ondocument 226:

TABLE I n sk_(n) s_(n) 1 george 2 2 university 2 3 located 1 4 four 1 5blocks 1 6 white 1 7 house 1 8 created 1 9 act 1 10 congress 1 11 1821 1(It should be noted that “Washington” is not a subordinate keywordbecause it is a primary keyword 212.)

The next step is to assign “weights” to each subordinate keyword. Somesubordinate keywords will undoubtedly be more important than others andassigning weights will enable the system to more accurately express thededuced intent of the user. The weight of each subordinate keyword isdetermined based on a number of factors, including, but not limited to,the placements of the keyword and frequencies with which it appears inthe links, descriptive text, meta-tags or any other informationassociated with documents referred to by the user, including thedocuments themselves.

Depending upon the behavior of the user, subordinate keywords can evenbe deemed to have negative weights, meaning that they represent ideas inwhich the user is not interested. In one embodiment of the system,negative keywords are generated from the titles and display texts ofdocuments that are passed over by the user. For example, if the userwere to click on the fourth document in a list of results, it can beinferred from the user's behavior that there is little or no interest inthe information presented in the first three results. As such, anysubordinate keywords present in the titles and display texts of thefirst three documents can be given a negative weight.

In one embodiment, subordinate keyword weights are further adjusted bysoliciting feedback from the user with respect to each document viewed.By requesting that the user indicate, on a scale, for example, theusefulness of a document just viewed, the system can adjust the extentto which the weights of the subordinate keywords associated with thatdocument are raised or lowered. In the absence of such feedback, otherinformation regarding the user's behavior, such as dwell time and anysort of activity, can be used to infer to what extent viewed documentsare interesting to the user.

In any event, the weight of a given subordinate keyword will be afunction that takes into account the locations and frequencies of itsappearances. Subordinate keywords that appear in some places, such astitles or display texts, may be given more weight than if they hadappeared elsewhere, such as buried in selected documents. Furthermore,subordinate keywords that appear in important documents may be givenmore weight than if they had appeared in less important documents.

If l_(n) represents the weight of the n^(th) subordinate keyword anda_(n) through z_(n), and possibly beyond, represent the frequency withwhich sk_(n) appears in various places in specific documents, such astitles, descriptive texts, links, meta-tags and so forth, then thefollowing represents a generalized formula for calculating subordinatekeyword weights:

l _(n) =f ₁(a _(n))+f ₂(b _(n))+f ₃(c _(n))+ . . .

One embodiment of the system might make the weight of a subordinatekeyword a function of the number of times it appears in the titles ordisplay texts of documents that have been selected by virtue of a userclick. As such, the following formula, using the arctangent function toprovide a mechanism for having the weights asymptotically approach agiven value as the frequency of appearances increases, could be used togenerate weights in the range of −100 to +100:

$1_{n} = {\left( \frac{200}{\pi} \right){\tan^{- 1}\left( \frac{s_{n}}{3} \right)}}$

(The purpose of asymptotically approaching a given value is to steadilydecrease the impact of the marginal appearance so that no one keywordoverwhelms the others.)

Using the data from TABLE I, TABLE II indicates the weights that wouldbe associated with each subordinate keyword by employing the formulaabove:

TABLE II n sk_(n) s_(n) l_(n) 1 george 2 37 2 university 2 37 3 located1 20 4 four 1 20 5 blocks 1 20 6 white 1 20 7 house 1 20 8 created 1 209 act 1 20 10 congress 1 20 11 1821 1 20

Continuing this example, if the user's second click was on document 256in FIG. 2C, with the title “George Washington University—OfficialAthletic Site” and display text “News, schedules, and information aboutthe athletics teams of George Washington University, as well,” thesubordinate keywords with their associated weights would look like TABLEIII:

TABLE III n sk_(n) s_(n) l_(n) 1 george 4 59 2 university 4 59 3 located1 20 4 four 1 20 5 blocks 1 20 6 white 1 20 7 house 1 20 8 created 1 209 act 1 20 10 congress 1 20 11 1821 1 20 12 official 1 20 13 news 1 2014 schedules 1 20 15 information 1 20 16 athletics 2 37 17 teams 1 20

Once the subordinate keywords have been generated and each assigned withan appropriate weight, the data is utilized to re-rank the matcheddocuments in the search results. Documents are increased (or decreased)in importance and moved up (or down) in the prioritization of the searchresults based on their association with the subordinate keywords. Withthe goal of dynamically re-ranking the search results to best reflectthe deduced intent of the user, a ranking algorithm must be developedand then tuned to specify the impact that each subordinate keyword hason the movement of the documents in the search results.

The ranking function will run through the search results and adjust therank of each matched document based on which subordinate keywords areassociated with each document, taking into account the weights of eachas well as where exactly they are found. The ranking function will,naturally, also take into account the previous rank of the document,helping to reflect, in some way, the intelligence that went intoproducing the initial order of the search results. Much as the weightsof the subordinate keywords were based on where and how often thosekeywords appeared in relation to the selected, or skipped, documents,the movement of matched documents in the search results will similarlydepend on where the subordinate keywords appear. A document with a largenumber of high-weight subordinate keywords in its title, display textand meta-tags will perhaps move much more dramatically than a documentwith a few low-weight subordinate keywords buried deep within the textof the document. It should also be noted that the presence ofsubordinate keywords with positive weights will increase the relevancyof the document, moving it up in the rankings, while the presence ofsubordinate keywords with negative weights will decrease the relevancyand have the opposite effect.

Thus, if M represents the number of matched documents returned by agiven query and r_(m) represents the rank of the m^(th) document thenthe generalized ranking function will look as follows:

${R(m)} = {{f_{R}\left( r_{m} \right)} + {\sum\limits_{n = 1}^{N}{f_{R\; 1}\left( {a_{n},l_{n}} \right)}} + {f_{R\; 2}\left( {b_{n},l_{n}} \right)} + {f_{R\; 3}\left( {c_{n},l_{n}} \right)} + \ldots}$

Since the actual relevancy scores as determined by the underlying searchengine are not necessarily available, the ranks of the matched documentsserve as a proxy for relevancy. However, if the underlying search enginewere to share the calculated relevancy scores of the matched documents,via some method of communication such as an API, or if the invention wasactually incorporated into the underlying search engine itself, thenthose relevancy scores could be used for r_(m), in place of the rank,potentially increasing the effectiveness of the system.

To illustrate, if t_(m) and d_(m) represent, respectively, the title anddisplay text of the m^(th) document, then TABLE IV is a depiction of thefirst eight search results as demonstrated in FIG. 2B:

TABLE IV m r_(m) t_(m) d_(m) 1 1 Access Washington Home LocateWashington State Government Page information and services available onthe Web. 2 2 University of Washington Offers information and news forprospective and current students, faculty, and staff. Highlights . . . 33 Experience Washington The official website of Washington State Tourismwith maps, history, and tourist attractions. 4 4 Washington DCConvention Official visitor information for Washington, and VisitorsAssociation DC—the Nation's Capital, WCTC Home. 5 5 Washington PostDaily. Offers news, opinion, sports, arts and living and entertainment.Includes archives since 1977 . . . 6 6 Washington News - New York Findbreaking news, multimedia & opinion Times from Washington including newson politics, the election, the President, Supreme Court, Congress andThe White . . . 7 7 George Washington University The George WashingtonUniversity is located four blocks from the White House and was createdby an Act of Congress in 1821. 8 8 NBA.com: Washington Official sitecontaining news, scores, audio Wizards and video files, playerstatistics and schedules.

One embodiment of the system might use a ranking function that makes thenew rank of a document equal to its previous rank plus some function ofthe subordinate keywords that appear in the document's title and displaytext. Where W_(r) and W_(s) represent constant weights and Er and Esrepresent constant exponents, such a ranking function, using the sgn( )and absolute value functions to handle negative subordinate keywordweights, could be displayed as follows:

${R(m)} = {{W_{r}r_{m}^{Er}} + {\sum\limits_{n = 1}^{N}{\begin{pmatrix}{{number}\mspace{14mu} {of}\mspace{14mu} {occurrences}} \\{{of}\mspace{14mu} {sk}_{n}\mspace{14mu} {in}\mspace{14mu} t_{m}\mspace{14mu} {and}\mspace{14mu} d_{m}}\end{pmatrix}W_{s}{{sgn}\left( 1_{n} \right)}{1_{n}}^{Es}}}}$

The values of the constants in the ranking function will be developed bycareful analysis of empirical user data. The objective is to determinethese values in order to optimize the movement of documents and minimizethe amount of searching required by the user to find the desiredinformation. One embodiment of the invention uses empirical user data asit is collected to refine the values of the constants in real time. Byidentifying the end of a successful search, possibly but not necessarilywith the help of feedback from the user, the system could, over time,adjust the values of the constants in order to maximize the percentageof searches that end successfully while minimizing the time required tocomplete a successful search. In one embodiment the constants areactually customized for each user, representing how different usersbehave differently, and stored in a user profile or cookie. In anotherembodiment, the constants also depend on other information such as thenumber of matched documents, which underlying search engine is beingused, the language of the results, the country where the user islocated, or virtually any other variable.

To illustrate how the ranking function works, when the subordinatekeywords in TABLE II are applied to the search result documents in TABLEIV, while setting W_(r), Er and Es to 1 and W_(s) to −½, the newrankings, R(m), are produced as displayed in TABLE V:

TABLE V m r_(m) R(m) t_(m) d_(m) 1 1 −9 Access Washington Home LocateWashington State Government Page information and services available onthe Web. 2 2 −16½ University of Washington Offers information and newsfor prospective and current students, faculty, and staff. Highlights . .. 3 3 3 Experience Washington The official website of Washington StateTourism with maps, history, and tourist attractions. 4 4 4 Washington DCConvention Official visitor information for and Visitors AssociationWashington, DC—the Nation's Capital, WCTC Home. 5 5 5 Washington PostDaily. Offers news, opinion, sports, arts and living and entertainment.Includes archives since 1977 . . . 6 6 −14 Washington News - New Findbreaking news, multimedia & York Times opinion from Washington includingnews on politics, the election, the President, Supreme Court, Congressand The White . . . 7 7 −157 George Washington The George WashingtonUniversity is University located four blocks from the White House andwas created by an Act of Congress in 1821. 8 8 8 NBA.com: WashingtonOfficial site containing news, scores, Wizards audio and video files,player statistics and schedules.

Using the first document (m=1) as an example, the only subordinatekeyword from TABLE II found in either the title, t₁, or display text,d₁, is “locate.” (Techniques, such as stemming, should be employed to,where appropriate, enable the broad matching of teems so that, forexample, “located”=“locate.” Artificial intelligence and contextualizedmatching can also be used to further enhance the term-matching abilityof the system.) Since the weight of the subordinate keyword is 20, theranking equation is thus 1+1×−½×20=−9. Using the second document (m=2)as another example, the only subordinate keyword from TABLE II found ineither the title, t₂, or display text, d₂, is “university,” which has aweight of 37. The ranking equation is thus 2+1×−½×37=−16½. Finally, theseventh document (m=7) represents a more complicated example. The twowords “george” and “university,” with weights of 37, both appear twicein the title, t₇, and display text, d₇. The nine words “located,”“four,” “blocks,” “white,” “house,” “created,” “act,” “congress,” and“1821” all appear once in the display text, d₇, and have weights of 20.The ranking function is thus 7+(2×−½×37)×2+(1×−½×20)×9=−157.

When sorted by R(m), and then resetting the values of r_(m) for the newrankings, the documents are rearranged as shown in TABLE VI:

TABLE VI m r_(m) R(m) t_(m) d_(m) 1 −157 −157 George Washington TheGeorge Washington University University is located four blocks from theWhite House and was created by an Act of Congress in 1821. 2 −16½ −16½University of Washington Offers information and news for prospective andcurrent students, faculty, and staff. Highlights . . . 3 −14 −14Washington News - New Find breaking news, multimedia & York Timesopinion from Washington including news on politics, the election, thePresident, Supreme Court, Congress and The White . . . 4 −9 −9 AccessWashington Home Locate Washington State Page Government information andservices available on the Web. 5 3 3 Experience Washington The officialwebsite of Washington State Tourism with maps, history, and touristattractions. 6 4 4 Washington DC Convention Official visitor informationfor and Visitors Association Washington, DC—the Nation's Capital, WCTCHome. 7 5 5 Washington Post Daily. Offers news, opinion, sports, artsand living and entertainment. Includes archives since 1977 . . . 8 8 8NBA.com: Washington Official site containing news, scores, Wizards audioand video files, player statistics and schedules.

Some of the new rankings are obviously negative. This does not present aproblem, however, since the matched documents are simply ordered fromthe lowest ranking to the highest. It should also be noted that thecalculations in TABLES V and VI will have to be executed on all of theresults as opposed to just the first eight, or even just those on thefirst page of the search results, as it is likely that documents fromsubsequent pages will be moved forward while others dropped back.

As a practical matter, computational limitations imposed by the serverhosting the invention software might prohibit running the rankingalgorithm on all of the matched documents generated by a query,especially if there are millions of them. Not only is processor speedrequired to execute all of the calculations, but the server memory mightneed to be large enough to hold all of the results. Fortunately, theranking algorithm can be run on a fairly large number of matcheddocuments, the first several hundred or thousand for example, withoutsignificantly impacting the effectiveness of the system. Should adetermined user page through a large proportion of those re-rankeddocuments, the system can simply grab the next batch of several hundredor thousand and quickly re-rank those with the previous batch. In anyevent, it is important to run as many computations as possible in thebackground while the user is reading or reviewing documents in order toavoid imposing delays on the user.

Should the ranking function take into account the presence ofsubordinate keywords in the actual documents, this could additionallyrequire a significant amount of bandwidth and processing power as eachdocument is downloaded and reviewed. A computational and time-savingtechnique, however, would be to use the power of the underlying searchengine, or even another search engine, to accelerate the speed withwhich subordinate keywords are identified in matched documents. Ratherthan scanning all of the matched documents for the presence ofsubordinate keywords, the system can, in the background, run queriesusing the subordinate keywords, or just the most important thereof tosave on computational time, in order to quickly determine which of thematched documents contain the recently generated subordinate keywords.At this point all that is required is a simple corresponding of theinitial matched documents with the results generated by the subordinatekeyword queries. The ranking function can then quickly take into accountthe presence of subordinate keywords in the matched documents themselvesand adjust the rankings accordingly.

FIG. 5 is a diagram of one embodiment of an “advanced search” page ofthe invention that actually displays the subordinate keywords to theuser. While the matched documents 510-516 and the sponsored links520-528 are the same, an “information bar” on the left-hand sidecontains the primary keywords 530 and subordinate keywords 531-550currently employed. The subordinate keywords can be shown in color, withblue representing positive subordinate keywords and red representingnegative subordinate keywords. While the actual color is not important,the intensity of the color corresponds with the weight: the more intensethe color, the more the weight is either positive or negative. Thesubordinate keywords would thus be listed from dark blue (very positive)to dark red (very negative).

Displaying the subordinate keywords can be beneficial to the user for acouple of reasons: not only does this give insight into how the systemis operating, but users can then assist the system in locating relevantdocuments by either manually removing or promoting specific subordinatekeywords. Should the user know that a particular subordinate keyword isnot relevant to the query, that keyword can be selected and then removedby pressing the “remove” button 560. Should the user see a subordinatekeyword that is deemed more than just important, but essential, to thequery, it can be selected and then promoted to a primary keyword bypressing the “promote” button 562. Once any set of keywords is promotedto primary the initial search will have to be rerun by returning to theunderlying search engine for a new set of results. That being said, allof the remaining subordinate keywords and weights can be carried forwardwith the new set of search results being adjusted accordingly.

Since the order of the matched documents changes every time a userreturns to the search results page, “bread crumbs” linking to previoussearch results pages 570-572 will enable the user, if so desired, to goback to previous rankings of matched documents. Additionally, since thissystem is a novel approach to assisting the user to find relevantdocuments, the movement of the matched documents might initially beconfusing. Nevertheless, a few things can thus be done with the userinterface to help ease the transition. “Movement indicators” can beplaced immediately to the left of document titles 510-517 to indicatehow the documents have moved since the last visit to the search resultspage (+6, +9, +13, etc.). Also, to further highlight which documentshave already been clicked or skipped, boxes of one color, such as blue,can be put around documents that have already been clicked 510 and 512while boxes of another color, such as red, can be put around documentsthat have previously been skipped 511 and 515-517. Finally, uponreturning to the search results page, the user can be placed at thefirst document that has yet to be selected or skipped. This will helpthe user to identify documents that have leapt high in the rankingsbefore continuing with the search process. Other techniques for helpingthe user understand the process of dynamically changing search resultsmay also be envisioned and implemented.

It should be emphasized, as stated earlier, that the sponsored links520-528 also change dynamically based on the deduced intent of the user.A third-party sponsored link service, that either accepts keywordsubmissions or scans the content of a page, can take subordinatekeywords into account to deliver relevant advertisements. Whether athird-party sponsored link service is used or not, subordinate keywords,since they are a representation of the deduced intent of the user,should be used to dynamically alter the sponsored links that aredisplayed. To the extent possible, the system should devise techniquesfor having the selection of sponsored links take the subordinatekeywords into consideration. Increasing the accuracy of targetedadvertisements that are displayed will have the dual benefit ofimproving the user experience while increasing the revenue generated bythe system.

The outcome is thus a dynamic results search engine that continuouslychanges, updates and reorganizes search results based upon the intent ofthe user as deduced from the ongoing behavior of the user during thesearch process. As the user clicks on links, views documents, executestransactions, downloads files, scrolls pages, adds or subtracts keywords(some of which can be taken from generated subordinate keywords),executes other queries, or performs almost any kind of activity, thesystem takes this information, deduces the intent of the user, generatessubordinate keywords and assigns weights to them before thenreprioritizing the search results “on the fly.” The end result is adynamic results search engine better able to assist users in findingdesired documents and information.

In one embodiment, user behavior monitoring is done by a first softwaremodule on server 132 in FIG. 1. The behavior information is provided toa second, re-ranking software module on server 132. The re-rankingmodule modifies the rankings of search results received from athird-party search engine and stores the re-ranked results on database130. The re-ranking software module also performs the highlighting,showing of ranking movement, displaying of subordinate keywords, andother functions not performed by the monitoring software module or thethird-party search engine. The re-ranked search results are supplied toa client browser on the user's computer. The client browser software mayperform some of the customized display functions of the invention.

In one embodiment, the re-ranking software module works in parallel withuser actions, performing re-ranking while the user behavior is beingmonitored. A series of re-ranked results can be created and stored indatabase 130 as the user clicks through documents. If the user decidesthat a particular document is not relevant, then the re-ranking moduletakes the subordinate keywords associated with that document, make theirweights negative, and pushes the document (and other that are similar)down.

The user browser may be installed on other devices than a computer, suchas a personal digital assistant (PDA), a mobile phone, or any otherdevice. The display can be modified to fit a smaller form factor, suchas by providing the sponsor links before or after a group of searchresults. In addition to the visual indicators described for re-ranking,weights of subordinate keywords, etc., audio indications could be used.Additionally, voice input can be used to remove or promote subordinatekeywords, or for any other user input.

As will be understood by those of skill in the art, the presentinvention could be embodied in other specific forms without departingfrom the essential characteristics thereof. For example, in addition tosubordinate keywords, data based on prior users' experiences and clickstreams could be used to re-rank the results in real time. This couldprovide two levels of ranking, (1) a first re-ranking using subordinatekeywords as described above, and (2) a re-ranking of the re-rankedresults using the webpages found most desirable by previous users doingsimilar searches.

The present invention can use a separate third party search engine, orcould be integrated with a search engine. The search engine could be ageneral search engine that searches the interne, a specialized searchengine that searches a particular web site, a database search engine, ameta-search engine that combines the results of multiple other searchengines, or any other type of search engine. Accordingly the foregoingdescription is intended to be illustrative, but not limiting, of thescope of the invention which is set forth in the following claims.

1.-21. (canceled)
 22. A method for dynamically modifying advertisementsassociated with search results comprising: receiving one or morekeywords for use as search terms from a user; providing a set of searchresult objects on a first page of results displayed to said user;providing a set of advertisement objects on said first page of results;monitoring which of said objects, search results and advertisements, isselected by said user; compiling information to infer user intent basedon analyzing the content of an object the user clicks; and upon saiduser clicking to return from said object to said set of search resultobjects including said object, immediately automatically re-ranking saidset of advertisement objects based on said user inferred intent, so thatupon said user returning from said object to said set of search resultobjects including said object, without the user resubmitting the search,the re-ranked advertisements will be visible; wherein said re-rankingincludes moving at least one advertisement object from a subsequentpage, not originally visible to said user on said first page, onto saidfirst page.
 23. The method of claim 22 further comprising: monitoringwhich objects said user skips; compiling information to infer userintent based on the content of said objects said user skips; and uponsaid user clicking to return from said selected object to said set ofsearch result objects including said selected object and said skippedobjects, immediately automatically re-ranking said set of advertisementobjects based on user intent inferred from said analyzing of the contentof said skipped objects, so that a user clicking on a single object fromsaid set of search result objects results in a re-ranking of said set ofobjects, so that upon said user returning from said object to said setof search result objects including said object, without the userresubmitting the search, the re-ranked advertisements will be visible.24. The method of claim 22 further comprising: selecting subordinatekeywords from the title and snippet of at least one of the objectsclicked on by the user, other links associated with an object includinglinks pointing to the object, descriptive text associated with eachobject in the search results, meta-tags connected to viewed objects,prominent words and phrases and their synonyms provided by a Thesaurusin viewed objects; and improving the ranking of advertisement objectscontaining said subordinate keywords.
 25. The method of claim 22 furthercomprising: using terms from the title and display text corresponding toobjects skipped by a user as negative subordinate keywords; and reducingthe ranking of advertisement objects containing said negativesubordinate keywords.
 26. The method of claim 24 further comprising:assigning weights to said subordinate keywords, such that objects havinghigher weighted subordinate keywords are given increased preference inthe ranking.
 27. The method of claim 24 further comprising: providing auser interface allowing a user to manually promote selected subordinatekeywords such that they have a higher weighting or are used as primarykeywords to generate new search results.
 28. The method of claim 24further comprising: providing a user interface allowing a user to deleteselected subordinate keywords.
 29. The method of claim 22 furthercomprising: doing said re-ranking based on information from searchesincluding said keywords in a same browser session; wherein saidproviding a first set of objects is performed by a separate searchengine software program from a user behavior program that performs saidmonitoring and generating steps.
 30. The method of claim 22 furthercomprising monitoring user behavior by at least one of: subsequentclicks on links within documents; dwell times; time spent looking atdocuments from specific domains; resources accessed; transactionsconducted; purchases made; orders placed; sessions created; documentsdownloaded; cursors moved; pages or text scrolled; and images or otherinformation highlighted.
 31. The method of claim 22 further comprising:rating the usefulness of at least one of said objects in response to auser rating input; and applying the user rating to said algorithm forgenerating said re-ranking.
 32. The method of claim 22 furthercomprising: providing a first display indication of objects that havebeen previously selected by said user; and providing a second displayindication of objects that have been skipped by said user.
 33. Themethod of claim 22 further comprising: providing a display indication ofthe ranking movement of said objects in said re-ranking of said firstset of objects, said ranking movement indicating an amount of a changein ranking of said objects.
 34. A system for dynamically modifyingsearch results comprising: a user interface on a first computerconfigured to receive one or more keywords for use as search terms froma user; a search engine on a server in communication with said firstcomputer over a network, said search engine being configured to providea set of search result objects on a first page of results displayed inresponse to said keywords and to provide some title and display textwith each of said search result objects in said set of search resultobjects and to provide a plurality of advertisement objects on saidfirst page of results; a monitoring program in communication with saidnetwork, said monitoring program being configured to monitor userbehavior in interacting with said search result and advertisementobjects; a re-ranking program configured to monitor which objects saiduser clicks on in interacting with said first set of objects; monitorwhich objects said user skips; compile information to infer user intentbased on analyzing the content of said objects the user clicks on andsaid objects said user skips; upon said user clicking to return from anobject to said set of search result objects including said object,immediately automatically re-rank said set of advertisement objectsbased on said inferred intent, so that a user clicking on a singleobject from said set of search result objects results in a re-ranking ofsaid set of advertisement objects, so that upon said user returning fromsaid object to said set of search result objects including said object,without the user resubmitting the search, the re-ranked advertisementwill be visible; and use terms from the title and display textcorresponding to a selected object in an algorithm for generating saidre-ranking of said set of advertisement objects on at least said firstpage; an advertising program configured to select and displayadvertising based on said inferred intent and immediately andautomatically re-ranking said plurality of advertisement objects on saidfirst page by adding at least one advertisement not previously shown onsaid first page.
 35. The system of claim 34 wherein said search engineis on a first server, and said monitoring and re-ranking programs are ona second server.
 36. A computer product having computer instructions oncomputer readable media executable by a processor to dynamically modifysearch results, comprising code for: receiving one or more keywords foruse as search terms from a user; providing a set of search resultobjects on a first page of results displayed; providing some title anddisplay text with each of said search result objects in said set ofsearch result objects; providing a set of advertisement objects on saidfirst page of results; monitoring which of said objects is selected bysaid user; monitoring which of said objects said user skips; compilinginformation to infer user intent based on analyzing the content of saidobjects the user clicks on and said objects said user skips; upon saiduser clicking to return from an object to said set of search resultobjects including said object, immediately automatically re-ranking saidfirst set of advertisement objects based on said inferred intent, sothat a user clicking on a single object from said set of search resultobjects results in a re-ranking of said set of advertisement objects, sothat upon said user returning from said object to said set of searchresult objects including said object, without the user resubmitting thesearch, the re-ranked advertisements will be visible; using terms fromthe title and display text corresponding to a selected object in analgorithm for generating said re-ranking of said set of objects on atleast said first page; wherein said re-ranking includes moving at leastone object from a subsequent page, not originally visible to said useron said first page, onto said first page; wherein said at least oneadvertisement object moved onto said first page is displayed in a mannerto indicate to the user that it has been inserted between other objectson said first page, with said display providing an indication that theobject is from a subsequent page and was not originally displayed onsaid first page
 37. A method for ranking a set of search results havingan initial ranking, comprising: providing some title and display textwith each of said search result objects on a first page of resultsdisplayed in said set of search result objects; monitoring which of saidobjects is selected by said user; determining one or more selectedobjects in said set of search results which corresponds to user interestbased on user behavior; monitoring which documents said user skips;compiling information to infer user intent based on the content of saidobject the user clicks on and said objects said user skips; upon saiduser clicking to return from an object to said set of search resultobjects including said object, immediately automatically re-ranking saidset of advertisement objects based on said user inferred intent, so thata user clicking on a single document from said first set of objectsresults in a re-ranking of said set of objects, so that upon said userreturning from said object to said set of search result objectsincluding said object, without the user resubmitting the search, there-ranked advertisements will be visible; using terms from the title anddisplay text corresponding to a selected object as positive subordinatekeywords for generating said re-ranking of said set of advertisementobjects; increasing the ranking of advertisement objects containingpositive subordinate keywords. using terms from the title and displaytext corresponding to objects skipped by a user as negative subordinatekeywords; reducing the ranking of advertisement objects containing saidnegative subordinate keywords; wherein said re-ranking includes movingat least one advertisement object from a subsequent page, not originallyvisible to said user on said first page, onto said first page; whereinsaid at least one advertisement object moved onto said first page isdisplayed in a manner to indicate to the user that it has been insertedbetween other objects on said first page, with said display providing anindication that the object is from a subsequent page and was notoriginally displayed on said first page.
 38. The method of claim 22wherein said selecting and displaying advertising based on said userbehavior further comprises: providing a plurality of advertisementobjects; and reordering said advertisement objects based on said userbehavior.
 39. The method of claim 22 wherein said performing saidselecting and displaying advertising objects based on said subordinatekeywords further comprises: allocating particular keywords to particularsponsors.
 40. The method of claim 31 wherein said rating the usefulnessof at least one of said search result objects in response to a userrating input further comprises: providing a search object rating for anindicated search object; adjusting the weights of subordinate keywordsassociated with said indicated search object in accordance with saidsearch object rating.
 41. The method of claim 22 further comprising:wherein said second set of objects are generated by using a separatesearch engine to perform a second search in the background, comparingthe results of said second search to said set of objects, and re-rankingsaid set of objects based on said results of said second search.
 42. Themethod of claim 25 further comprising: assigning weights to saidnegative subordinate keywords, such that objects having higher weightedsubordinate keywords are given decreased preference in the ranking. 43.The method of claim 25 further comprising: providing a user interfaceallowing a user to manually demote selected negative subordinatekeywords such that they have a higher weighting.
 44. The method of claim25 further comprising: providing a user interface allowing a user todelete selected negative subordinate keywords.